The last few years have seen the introduction of the concept of "extensions" in most popular web browsers. While Mozilla natively supports extensions, Opera and Safari come feature-packed and can be easily hacked via config files, and a market has cropped up around the IE engine which supports adding new functionality to your browser. In the interest of sharing a good thing, which are your favorite browser extensions?

I'm glad to hear that. I don't mean to diss your site - when I was using AdBlock to protect my browser, I tried blocking NetShelter and it made OSNews not work properly. That was probably a temporary glitch though.

I suppose it doesn't matter now, as NoScript disables AdBlock anyway, and makes it mostly unnecessary.